Whats the chance of getting pregnant a day before ovulation?

Good: Sperm need to be present in your reproductive track prior to ovulation. If the cervical mucus is normal then it should support sperm survival for at least 24 to 72 hours prior to ovulation.

Pretty high!: Sperm can last in the woman's reproductive tract for almost a week. If there is a sperm waiting for an egg as it is released, pregnancy can occur unless you have some type of protection, i.e. Condoms, birth control pills, etc. If you want to avoid getting pregnant, the morning after pill is a good option as long as it is taken within 72 hours of unprotected intercourse.